Field of the Invention
The present invention relates to a coupling device for hoisting machines.
Brief Description of the Related Art
In the shaft and inclined hoisting technology, so-called double-drum hoisting machines or double-drum Blair hoisting machines are used at small depths of up to 500 m and at great depths of 1,750 m to 3,000 m, said hoisting machines counteractively coiling and/or uncoiling one or two ropes per drum.
As a rule, at least one of the drums is configured as a loose drum and the other possibly as a fixed drum. The loose drum which is rotatably mounted on the main shaft via sliding bushings or rolling bearings is connected to the main shaft with a coupling device.
This coupling device must be configured as a switchable clutch (coupling and uncoupling) in order to be able to move the two drums relative to each other at any given time in standstill with engaged loose-drum brake.
In the course of the lifespan of hoisting ropes, the extension and the elongation of the ropes changes due to stresses during hoisting operation and self-weights. Since the different ropes of the corresponding drums always extend in differently large degrees in the process, in two-drum hoisting operation it must always be possible to move the two drums of a double-drum hoisting machine or of a double-drum Blair hoisting machine relative to each other in order to ensure a uniform and safe positioning of the one conveying means in the loading location at an underground work level and of the other conveying means in the unloading location. With a constellation of the described type it is possible to achieve, among other things, a compensation of rope elongations in loading and unloading locations.
However, at the same time, it can also occur in shaft and inclined hoisting operation that the hoisting of the hoisted material is to be relocated from one work level to another work level further above or below. Also for this purpose it must be possible to move the two drums of the hoisting machine relative to each other, in order to ensure a simultaneous positioning of the one conveying means in the unloading location and of the other conveying means in the loading location at the respective underground work level. A device of the described type also makes it possible, however, to approach different underground work levels correspondingly fast and accurately, while unloading takes place simultaneously on the surface.
Known coupling devices have e.g. a shaft wheel toothed on the outside and a drum wheel with interior toothing, both of which are mutually connected via an axially movable coupling or sliding wheel having interior and exterior toothing.
The toothing of the shaft wheel is as a rule configured such that it serves as guide toothing when the flank clearance is relatively small and always remains engaged with the interior toothing of the sliding wheel also in the uncoupled coupling state of the device.
These devices are switched via a non-rotating displacement collar/adjusting ring guided on the machine frame, said collar moving the coupling or sliding wheel having the interior and exterior toothing back and forth in an axial direction, and being able to couple and uncouple the toothing in the process. The displacing collar/adjusting ring is actuated here e.g. via two double-action hydraulic cylinders, which are possibly coupled with the displacing collar/adjusting ring via a knee-lever system.
It is disadvantageous in this arrangement that relative movements always occur between the stationary displacement collar/adjusting ring and the rotating coupling wheel during the normal hoisting operation. These relative movements lead to wear and ensuing maintenance effort. Further, these points represent potential disturbances. The relative movement also has a negative effect on the heating and the ensuing deformation of the components, additionally increasing the wear.